ABSTRACT
Branchial cleft cysts are congenital diseases of the neck caused by abnormal embryonic development of the first to fourth branchial clefts. Most branchial cleft cysts are found in the head and neck, but branchial cleft cysts arising in posterior mediastinum are rarely reported. We report a 44-year-old Chinese man who was found to have a right-posterior mediastinal mass on chest computed tomography (CT) during a physical examination. The size of the mass was about 30.6â mm * 25.1â mm and enhanced CT of the chest showed an occupying lesion in the right parietal esophagus of the upper-posterior mediastinum with no significant enhancement. The patient was considered to have a neurogenic tumor with cystic change and underwent posterior mediastinal tumor resection. Postoperatively, pathological examination confirmed the final diagnosis of bronchial cleft cyst. The patient was discharged on the 7th day after surgery. One year postsurgery, no obvious recurrence was found in reexamination.
ABSTRACT
BACKGROUND: Pulmonary tuberculosis (TB) and lung cancer (LC) are common diseases with a high incidence and similar symptoms, which may be misdiagnosed by radiologists, thus delaying the best treatment opportunity for patients. AIM: To develop and validate radiomics methods for distinguishing pulmonary TB from LC based on computed tomography (CT) images. METHODS: We enrolled 478 patients (January 2012 to October 2018), who underwent preoperative CT screening. Radiomics features were extracted and selected from the CT data to establish a logistic regression model. A radiomics nomogram model was constructed, with the receiver operating characteristic, decision and calibration curves plotted to evaluate the discriminative performance. RESULTS: Radiomics features extracted from lesions with 4 mm radial dilation distances outside the lesion showed the best discriminative performance. The radiomics nomogram model exhibited good discrimination, with an area under the curve of 0.914 (sensitivity = 0.890, specificity = 0.796) in the training cohort, and 0.900 (sensitivity = 0.788, specificity = 0.907) in the validation cohort. The decision curve analysis revealed that the constructed nomogram had clinical usefulness. CONCLUSION: These proposed radiomic methods can be used as a noninvasive tool for differentiation of TB and LC based on preoperative CT data.
ABSTRACT
A novel nacre-like flame-retardant paper based on graphene oxide (GO), and phytic acid (PTA) is fabricated via evaporation-induced self-assembly. This facile method is time saving and low energy consuming. A facile approach is proposed to improve thermal oxidative stability of GO paper by in situ phosphorus doping during flame exposure. Then fire-alarm system is designed based on the high-temperature thermal reduction characteristic of GO. The GO paper functionalized with PTA (GO-PTA) can provide ultrasensitive, reliable and longtime fire early-warning signal. Fire alarm can be triggered at approximately 0.50 s when GO-PTA samples are attacked by fire. Phosphorus atoms are in situ doped into graphene layers during fire exposure, endowing GO-PTA paper with outstanding thermal oxidative stability, and thus alarm duration time of GO is greatly improved. The work develops advanced fire detection and early-warning sensors that provide reliable and continuous signals, which provide more available time for fire evacuation.
ABSTRACT
Flame propagation characteristics of wood dust deflagration and suppression mechanism of ultrafine powders are investigated systematically. The deflagration reaction intensity of wood dust increases firstly and then decreases with the increase in dust cloud concentration. This is due to factors such as oxygen supply, positive feedback among flame characteristic parameters. Thus, there is an equivalent dust concentration for greatest deflagration intensity. Nano-sized ultrafine zirconium hydroxide (Zr(OH)4) and silicon dioxide (SiO2) powder are introduced to suppress wood dust deflagration at the equivalent concentration. It is found that Zr(OH)4 has a suppression effect of endothermic decomposition to generate zirconia (ZrO2), dilution of oxygen and absorption of free radicals; while SiO2 exerts suppression effect due to its high melting point and heat absorption. The suppression performance of Zr(OH)4 is better than that of SiO2. This is because that Zr(OH)4 and ZrO2 have a catalytic carbonization effect. It can not only improve thermal stability of wood particles by catalyzing production of high-temperature resistant residuals, but also promote the formation of catalytic sites to reduce crystallite size of carbon layer on wood particles surface, weakening heat and mass transfer between particles.
ABSTRACT
Melamine-phytate (MEL-PA) nanoflakes are formed by supramolecular self-assembly technology using melamine (MEL) and bio-based phytic acid (PA) as the building blocks. This work explores the possibility of this two-dimensional nanomaterial as flame retardant. The layered MEL-PA with the loading of 1, 2 and 3â¯wt% are incorporated into polypropylene (PP) matrix. MEL-PA is dispersed well in the PP matrix. Thermal stability and flame retardant performance of PP/MEL-PA composites are investigated. Compared with neat PP, the addition of 2â¯wt% MEL-PA decreases the peak heat release rate from 756 to 608â¯kW/m2. Char yield of PP is improved by MEL-PA, and the chemical structure and graphitization degree of residual char are studied to reveal flame retardant mechanism.
ABSTRACT
As mobile payments become increasingly popular, the security of the transaction process should be taken more seriously. Many mobile phones are equipped with complementary metal-oxide-semiconductor (CMOS) cameras, which can be used as visible light communication (VLC) receivers. An optical camera communication (OCC) system is a special VLC system that uses an optical camera as a receiver. OCC offers acceptable security, but challenges remain. In this paper, we propose an OCC system that uses an optical camera with a rolling shutter as a receiver and a light-emitting diode (LED) panel light as a transmitter. The feature of an LED panel light serving as a surface light source reduces the possibility of overexposure and avoids the blooming effect of the camera. The rolling shutter effect of the CMOS camera is used to increase the data rate, which is numerically much higher than the frame rate. Finally, the results of a symbol error rate (SER) test show that the VLC system exhibits error-free performance. The data rate is approximately 4.2 kb/s, while the net data rate is approximately 2.46 kb/s due to the redundancy of the 3-9 code bar code and the redundant cycle. This data rate is sufficient for mobile payments, which require only 60 bits of data at a time.
ABSTRACT
In recent years, paper-based point-of-care testing (POCT) has been widely used in medical diagnostics, food safety and environmental monitoring. However, a high-cost, time-consuming and equipment-dependent sample pretreatment technique is generally required for raw sample processing, which are impractical for low-resource and disease-endemic areas. Therefore, there is an escalating demand for a cost-effective, simple and portable pretreatment technique, to be coupled with the commonly used paper-based assay (e.g. lateral flow assay) in POCT. In this review, we focus on the importance of using paper as a platform for sample pretreatment. We firstly discuss the beneficial use of paper for sample pretreatment, including sample collection and storage, separation, extraction, and concentration. We highlight the working principle and fabrication of each sample pretreatment device, the existing challenges and the future perspectives for developing paper-based sample pretreatment technique.
Subject(s)
Environmental Monitoring/methods , Food Safety/methods , Microfluidic Analytical Techniques/methods , Point-of-Care Systems/trends , Humans , Paper , Point-of-Care TestingABSTRACT
The effect of sodium chloride (NaCl) on cadmium (Cd) uptake, translocation, and oxidative stress was investigated using 2 tobacco cultivars differing in Cd tolerance. The growth inhibition of the tobacco plants exposed to Cd toxicity was in part alleviated by moderate addition of NaCl in the culture solution. Cadmium concentration of shoots and roots in the 2 cultivars increased with increasing Cd levels in the solution and decreased with the addition of NaCl. The addition of NaCl could alleviate the oxidative stress caused by Cd toxicity, as reflected by reduced production of malondialdehyde and recovered or enhanced activities of antioxidative enzymes catalase and glutathione peroxidase. The results also showed that the enhancement of antioxidative enzyme activity by NaCl for the tobacco plants exposed to Cd stress is related to induced Ca signaling.
Subject(s)
Adaptation, Physiological , Cadmium/toxicity , Nicotiana/physiology , Sodium Chloride/metabolism , Soil Pollutants/toxicity , Catalase/metabolism , Glutathione Peroxidase/metabolism , Malondialdehyde/metabolism , Oxidation-Reduction , Oxidative Stress , Plant Roots/drug effects , Plant Roots/metabolism , Sodium Chloride/chemistry , Soil/chemistry , Soil Pollutants/metabolism , Nicotiana/drug effectsABSTRACT
In the title compound, C(14)H(11)BrN(2)O(2), the mean planes of the two benzene rings are almost parallel to each other, making a dihedral angle of 4.09â (1)°. An intra-molecular O-Hâ¯N hydrogen bond occurs. In the crystal, inter-molecular O-Hâ¯N and C-Hâ¯O hydrogen bonds link the mol-ecules into a chain-like supra-molecular structure.
ABSTRACT
In the title compound, C(26)H(24)N(4)O(2), the dihedral angles between the central pyrazole ring and the other three benzene rings are 40.02â (3), 77.51â (5) and 55.72â (3)°. A strong intra-molecular N-Hâ¯O hydrogen bond forms a six-membered ring with an S(6) motif. In the crystal structure, a weak inter-molecular C-Hâ¯N inter-action with graph-set motif R(2) (2)(8) and C-Hâ¯O hydrogen bonds link each mol-ecule to three others, forming an infinite two-dimensional supra-molecular structure.
ABSTRACT
The complete mol-ecule of the title compound, C(22)H(28)N(2)O(4), is generated by a crystallographic inversion centre at the mid-point of the central C-C bond. The two benzene rings are parallel to each other with a perpendicular inter-planar spacing of 1.488â (2)â Å. Intra-molecular O-Hâ¯N hydrogen bonds generate two six-membered rings with S(6) motifs. In the crystal, weak inter-molecular C-Hâ¯O hydrogen bonds link neighbouring mol-ecules into an infinite three-dimensional network, which is further stabilized by weak C-Hâ¯π inter-actions.
ABSTRACT
The title complex, [Cu(C(26)H(22)N(2)O(4))], is isostructural with its Ni analogue. All intramolecular distances and angles are very similar for the two structures, whereas the packing of the molecules, including C-Hâ¯O and C-Hâ¯π interactions, are slightly different.
ABSTRACT
In the title complex, [Ni(C(26)H(22)N(2)O(4))], the Ni(II) atom has a slight distortion toward tetra-hedral geometry from a square-planar structure, coordinated by two O and two N atoms of the tetra-dentate salen-type bis-oxime 2,2'-[1,1'-(ethyl-enedioxy-dinitrilo)diethyl-idyne]di-1-naphtholate (L(2-)) unit, with a mean deviation of 0.022â Å from the N(2)O(2) plane. The N- and O-donor atoms are mutually cis. The dihedral angle between two naphthalene systems of the L(2-) ligand is 67.59â (4)°. The crystal structure is stabilized by inter-molecular C-Hâ¯O and C-Hâ¯π inter-actions, which link neighbouring mol-ecules into extended chains along the b axis.
ABSTRACT
The complete molecule of the title compound, C(26)H(24)N(2)O(4), is generated by a crystallographic centre of inversion. There are two intra-molecular O-Hâ¯N hydrogen bonds. In the crystal structure, inter-molecular C-Hâ¯O hydrogen bonds result in zigzag chains.
ABSTRACT
The mol-ecule of the title compound, C(31)H(34)N(2)O(4), adopts an L-shaped configuration, in which the naphthalene units are approximately perpendicular, making a dihedral angle of 87.89â (3)°. Intramolecular H-bonds are formed between the OH substituents and the N atoms at each end of the molecule. In the crystal structure, each mol-ecule links six other mol-ecules into an infinite three-dimensional network supra-molecular structure, which is built from one-dimensional zigzag chains via weak C-Hâ¯π stacking and inter-molecular C-Hâ¯O hydrogen bonds.
ABSTRACT
The title compound, C(29)H(30)N(2)O(4), adopts a distorted Z configuration with respect to the oxime group, which is almost coplanar with the adjacent naphthalene ring [dihedral angle = 4.11â (2)°]. There is one half-mol-ecule in the asymmetric unit, with a crystallographic twofold rotation axis passing through the central C atom of the -CH=N-O-(CH)(5)-O-N=CH- bridge. Within the mol-ecule, the dihedral angle formed by the two naphthalene rings is 79.08â (3)°, and there are two intra-molecular O-Hâ¯N hydrogen bonds.
ABSTRACT
The salen-type bis-oxime title compound, C(26)H(36)N(2)O(4), lies about a crystallographic inversion centre. Classical intra-molecular O-Hâ¯N hydrogen bonds generate two S(6) ring motifs. In the crystal structure, pairs of weak inter-molecular C-Hâ¯O hydrogen bonds link adjacent mol-ecules into an infinite one-dimensional supra-molecular structure.
ABSTRACT
The title compound, C(24)H(32)N(2)O(4), has a crystallographic inversion centre at the mid-point of the central C-C bond. At each end of the mol-ecule, intra-molecular O-Hâ¯N hydrogen bonds generate six-membered S(6) ring motifs. The crystal structure is stabilized by pairs of weak inter-molecular C-Hâ¯O hydrogen bonds that link neighbouring mol-ecules into R(2) (2)(40) ring motifs, which in turn form infinite one-dimensional supra-molecular ribbon structures.
ABSTRACT
The title compound, [Cu(C(9)H(9)BrNO(2))(2)], is a centrosymmetric mononuclear copper(II) complex. The Cu atom is four-coordinated in a trans-CuN(2)O(2) square-planar geometry by two phenolate O and two oxime N atoms from two symmetry-related N,O-bidentate (E)-4-bromo-2-(ethoxy-imino-meth-yl)phenolate oxime-type ligands. An inter-esting feature of the crystal structure is the centrosymmetric inter-molecular Cuâ¯O inter-action [3.382â (1)â Å], which establishes an infinite chain structure along the b axis.
ABSTRACT
In the title centrosymmetric mononuclear copper(II) complex, [Cu(C(8)H(7)BrNO(2))(2)], the Cu(II) atom, lying on an inversion centre, is four-coordinated in a trans-CuN(2)O(2) square-planar geometry by two phenolate O atoms and two oxime N atoms from two symmetry-related N,O-bidentate oxime-type ligands. Inter-molecular C-Hâ¯O hydrogen bonds link neighbouring mol-ecules into a one-dimensional supra-molecular structure with an R(2) (2)(14) ring motif. This structure is further stabilized by π-π stacking inter-actions between adjacent benzene rings [centroid-centroid distance = 3.862â (1)â Å].